[React Native Gallery -> Flyout]: No border for 'Open Popup' button.

[Yajur-Grover]

Build Details:
OS Version: Dev (OS Build 27695.1000)
App: React Native Gallery
App Version: 1.0.18.0
React Native Windows Version: 0.75.0

Repro-Steps:
Launch the React Native Gallery app.
Navigate to ‘All samples’ button present in left navigation pane and invoke it.
Navigate to ‘Flyout’ button present under “Dialogs & flyouts” group and invoke it.
Now observe 'Open Popup' button.
Actual Result:
No border for 'Open Popup' button. Visually it is looking as a static text.

Expected Result:
Proper border should be defined for 'Open Popup' button.

Link to ADO bug: https://microsoft.visualstudio.com/OS/_workitems/edit/54110241